Pulse width modulation (PWM) is widely used. PWM may meet the circuit specification by switching and may be used in the field such as biomedical technology, industry, science, smart grid, etc. Pulse width generators are generally implemented using analog circuits. However, most analog pulse width generators have large area and long response time. In addition, analog circuits may need to be re-designed for different fabrication processes. Thus, it is the trend to develop pulse width generators implemented with digital circuits.